WOLFRAM SYSTEMMODELER

ThickEdgedOrifice

Thicked edged orifice flow model

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Fluid.Fittings.Orifices.ThickEdgedOrifice"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This component models a thick edged orifice with sharp corners in the overall flow regime for incompressible and single-phase fluid flow through an arbitrary shaped cross sectional area (square, circular, etc.) considering influence of surface roughness. It is expected that also compressible fluid flow can be handled up to about Ma = 0.3. It is assumed that neither mass nor energy is stored in this component. In the model basically a function is called to compute the mass flow rate as a function of pressure loss for a thick edged orifice. Also the inverse of this function is defined, and a tool might use this inverse function instead, in order to avoid the solution of a nonlinear equation.

The details of the model are described in the documentation of the underlying function.

Parameters (7)

allowFlowReversal

Value: system.allowFlowReversal

Type: Boolean

Description: = true to allow flow reversal, false restricts to design direction (port_a -> port_b)

dp_start

Value: 0.01 * system.p_start

Type: AbsolutePressure (Pa)

Description: Guess value of dp = port_a.p - port_b.p

m_flow_start

Value: system.m_flow_start

Type: MassFlowRate (kg/s)

Description: Guess value of m_flow = port_a.m_flow

m_flow_small

Value: if system.use_eps_Re then system.eps_m_flow * system.m_flow_nominal else system.m_flow_small

Type: MassFlowRate (kg/s)

Description: Small mass flow rate for regularization of zero flow

show_T

Value: true

Type: Boolean

Description: = true, if temperatures at port_a and port_b are computed

show_V_flow

Value: true

Type: Boolean

Description: = true, if volume flow rate at inflowing port is computed

geometry

Value:

Type: Geometry

Description: Geometry of thick edged orifice

Connectors (2)

port_a

Type: FluidPort_a

Description: Fluid connector a (positive design flow direction is from port_a to port_b)

port_b

Type: FluidPort_b

Description: Fluid connector b (positive design flow direction is from port_a to port_b)

Components (5)

system

Type: System

Description: System wide properties

state_a

Type: ThermodynamicState

Description: state for medium inflowing through port_a

state_b

Type: ThermodynamicState

Description: state for medium inflowing through port_b

state_dp_small

Type: ThermodynamicState

Description: Medium state to compute dp_small

geometry

Type: Geometry

Description: Geometry of thick edged orifice